Power supply architecture for USB-C controllers

ABSTRACT

A power supply architecture for USB Type-C controllers is described herein. In an example embodiment, an integrated circuit (IC) controller comprises a power rail, a VDDD terminal, a VCONN terminal, and a VBUS terminal. The VDDD terminal, the VCONN terminal, and the VBUS terminal are coupled to the power rail, where a VCONN switch is coupled between the VCONN terminal and the power rail, and a VBUS regulator is coupled between the VBUS terminal and the power rail. The power rail is coupled to internal circuits of the IC controller and is configured to provide operating power to the internal circuits from any one of the VCONN terminal and the VBUS terminal.

PRIORITY

This application claims the priority and benefit of U.S. ProvisionalApplication No. 62/674,326, filed on May 21, 2018 and U.S. ProvisionalApplication No. 62/721,347, filed on Aug. 22, 2018, all of which areincorporated by reference herein in their entirety.

TECHNICAL FIELD

This disclosure relates to integrated circuits (ICs) that controlUniversal Serial Bus (USB) power delivery to electronic devices.

BACKGROUND

Various electronic devices (e.g., such as smartphones, tablets, notebookcomputers, laptop computers, chargers, adapters, power banks, etc.) areconfigured to transfer power through USB connectors according to USBpower delivery protocols defined in various versions and revisions ofthe USB Power Delivery (USB-PD) specification. For example, in someapplications an electronic device may be configured as a power consumerto receive power through a USB connector (e.g., for battery charging),while in other applications an electronic device may be configured as apower provider to provide power to another device that is connectedthereto through a USB connector. The USB-PD specification defines atleast three different voltage supplies: VBUS (e.g., 3V-22.5V, forpowering various USB functions), VCONN (e.g., 3.0V-5.5V, for powering aUSB Type-C chip), and a local battery supply (e.g., 2.0V-5.5V, forpowering internal on-chip circuitry). Thus, electronic devicemanufacturers typically use different types of IC controllers that arepowered from different power supplies depending on the different designsand/or applications of their USB-enabled electronic devices.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an on-die IC controller with a USB-PD subsystem inaccordance with example embodiments.

FIG. 2 illustrates a schematic diagram of an example power supplyarchitecture for a USB IC controller, according to some embodiments.

FIG. 3 illustrates a schematic diagram of an example VCONN switcharchitecture for a USB IC controller, according to some embodiments.

FIG. 4 illustrates a schematic diagram of an example VBUS regulatorarchitecture for a USB IC controller, according to some embodiments.

FIGS. 5A and 5B collectively illustrate a schematic diagram of a USBType-C cable assembly according to an example embodiment, where FIG. 5Aillustrates one end of the cable and FIG. 5B illustrates the other endof the cable.

FIG. 6 illustrates a schematic diagram of a USB-PD power adapter,according to an example embodiment.

FIG. 7 illustrates a schematic diagram of a VCONN switch architecture,according to an example embodiment.

FIG. 8 illustrates a schematic diagram of a power supply architecturewith off-chip voltage protection circuits, according to an exampleembodiment.

DETAILED DESCRIPTION

The following description sets forth numerous specific details such asexamples of specific systems, components, methods, and so forth, inorder to provide a good understanding of various embodiments of thepower supply architecture for USB Type-C controllers described herein.It will be apparent to one skilled in the art, however, that at leastsome embodiments may be practiced without these specific details. Inother instances, well-known components, elements, or methods are notdescribed in detail or are presented in a simple block diagram format inorder to avoid unnecessarily obscuring the subject matter describedherein. Thus, the specific details set forth hereinafter are merelyexemplary. Particular implementations may vary from these exemplarydetails and still be contemplated to be within the spirit and scope ofthe present invention.

Reference in the description to “an embodiment”, “one embodiment”, “anexample embodiment”, “some embodiments”, and “various embodiments” meansthat a particular feature, structure, step, operation, or characteristicdescribed in connection with the embodiment(s) is included in at leastone embodiment of the invention. Further, the appearances of the phrases“an embodiment”, “one embodiment”, “an example embodiment”, “someembodiments”, and “various embodiments” in various places in thedescription do not necessarily all refer to the same embodiment(s).

The description includes references to the accompanying drawings, whichform a part of the detailed description. The drawings show illustrationsin accordance with exemplary embodiments. These embodiments, which mayalso be referred to herein as “examples”, are described in enough detailto enable those skilled in the art to practice the embodiments of theclaimed subject matter described herein. The embodiments may becombined, other embodiments may be utilized, or structural, logical, andelectrical changes may be made without departing from the scope andspirit of the claimed subject matter. It should be understood that theembodiments described herein are not intended to limit the scope of thesubject matter but rather to enable one skilled in the art to practice,make, and/or use the subject matter.

Described herein are various embodiments of a power supply architecturein USB Type-C controllers that can be disposed to operate in variouselectronic devices. Examples of such electronic devices include, withoutlimitation, personal computers (e.g., laptop computers, notebookcomputers, etc.), mobile computing devices (e.g., tablets, tabletcomputers, e-reader devices, etc.), mobile communication devices (e.g.,smartphones, cell phones, personal digital assistants, messagingdevices, pocket PCs, etc.), connectivity and charging devices (e.g.,cables, hubs, docking stations, adapters, chargers, etc.),audio/video/data recording and/or playback devices (e.g., cameras, voicerecorders, hand-held scanners, monitors, etc.), and other similarelectronic devices that can use USB interfaces for communication,battery charging, and/or power delivery.

As used herein, “USB-enabled” device or system refers to a device orsystem that includes, is configured with, or is otherwise associatedwith a USB connector interface. A USB-enabled electronic device maycomply with at least one release of a Universal Serial Bus (USB)specification. Examples of such USB specifications include, withoutlimitation, the USB Specification Revision 2.0, the USB 3.0Specification, the USB 3.1 Specification, the USB 3.2 Specificationand/or various supplements, versions and errata thereof. The USBspecifications generally define the characteristics (e.g., attributes,protocol definition, types of transactions, bus management, programminginterfaces, etc.) of a differential serial bus that are required todesign and build standard communication systems and peripherals. Forexample, a USB-enabled peripheral device attaches to a USB-enabled hostdevice through a USB port of the host device to form a USB-enabledsystem. A USB 2.0 port includes a power voltage line of 5V (denotedVBUS), a differential pair of data lines (denoted D+ or DP, and D− orDN), and a ground line for power return (denoted GND). A USB 3.0 portalso provides the VBUS, D+, D−, and GND lines for backward compatibilitywith USB 2.0. In addition, to support a faster differential bus (the USBSuperSpeed bus), a USB 3.0 port also provides a differential pair oftransmitter data lines (denoted SSTX+ and SSTX−), a differential pair ofreceiver data lines (denoted SSRX+ and SSRX−), a power line for power(denoted DPWR), and a ground line for power return (denoted DGND). A USB3.1 port provides the same lines as a USB 3.0 port for backwardcompatibility with USB 2.0 and USB 3.0 communications, but extends theperformance of the SuperSpeed bus by a collection of features referredto as Enhanced SuperSpeed.

A more recent technology for USB connectors, called USB Type-C (alsoreferred to herein as “USB-C”), is defined in various releases and/orversions of the USB Type-C specification (e.g., such as Release 1.0dated Aug. 11, 2014, Release 1.1 dated Apr. 3, 2015, Release 1.2 datedMar. 25, 2016, Release 1.3 dated Jul. 14, 2017, or otherrevisions/versions thereof). The USB Type-C specification defines Type-Creceptacle, Type-C plug, and Type-C cables that can support USBcommunications as well as power delivery over newer USB power deliveryprotocols defined in various revisions/versions of the USB-PDspecification. Examples of USB Type-C functions and requirements mayinclude, without limitation, data and other communications according toUSB 2.0 and USB 3.0/3.1, electro-mechanical definitions and performancerequirements for Type-C cables, electro-mechanical definitions andperformance requirements for Type-C receptacles, electro-mechanicaldefinitions and performance requirements for Type-C plugs, requirementsfor Type-C to legacy cable assemblies and adapters, requirements forType-C-based device detection and interface configuration, requirementsfor optimized power delivery for Type-C connectors, etc. According tothe USB Type-C specification(s), a Type-C port provides VBUS, D+, D−,GND, SSTX+, SSTX−, SSRX+, and SSRX− lines, among others. In addition, aType-C port also provides a Sideband Use (denoted SBU) line forsignaling of sideband functionality and a Configuration Channel (denotedCC) line for discovery, configuration, and management of connectionsacross a Type-C cable. A Type-C port may be associated with a Type-Cplug and/or a Type-C receptacle. For ease of use, the Type-C plug andthe Type-C receptacle are designed as a reversible pair that operatesregardless of the plug-to-receptacle orientation. Thus, a standard USBType-C connector, disposed as a standard Type-C plug or receptacle,provides pins for four VBUS lines, four ground return (GND) lines, twoD+ lines (DP1 and DP2), two D− lines (DN1 and DN2), two SSTX+ lines(SSTXP1 and SSTXP2), two SSTX− lines (SSTXN1 and SSTXN2), two SSRX+lines (SSRXP1 and SSRXP2), two SSRX− lines (SSRXN1 and SSRXN2), two CClines (CC1 and CC2), and two SBU lines (SBU1 and SBU2), among others.

Some USB-enabled electronic devices may be compliant with a specificrevision and/or version of the USB-PD specification (e.g., such asRevision 1.0 released Jul. 5, 2012, Revision 2.0 released Aug. 11, 2014,Revision 3.0 dated Mar. 25, 2016, or other revisions/versions thereof).The USB-PD specification defines a standard protocol designed to enablethe maximum functionality of USB-enabled devices by providing moreflexible power delivery along with data communications over a single USBType-C cable through USB Type-C ports. The USB-PD specification alsodescribes the architecture, protocols, power supply behavior,parameters, and cabling necessary for managing power delivery over USBType-C cables at up to 100 W of power. According to the USB-PDspecification, devices with USB Type-C ports (e.g., such as USB-enableddevices) may negotiate for more current and/or higher or lower voltagesover a USB Type-C cable than are allowed in older USB specifications(e.g., such as the USB 2.0 Specification, USB 3.1 Specification, the USBBattery Charging Specification Rev. 1.1/1.2, etc). For example, theUSB-PD specification defines the requirements for a power deliverycontract (PD contract) that can be negotiated between a pair ofUSB-enabled devices. The PD contract can specify both the power leveland the direction of power transfer that can be accommodated by bothdevices, and can be dynamically re-negotiated (e.g., without deviceun-plugging) upon request by either device and/or in response to variousevents and conditions, such as power role swap, data role swap, hardreset, failure of the power source, etc. As used herein, “USB-PDsubsystem” refers to one or more logic blocks and other analog/digitalhardware circuitry, which may be controllable by firmware in an ICcontroller and which is configured and operable to perform the functionsand to satisfy the requirements specified in at least one release of theUSB-PD specification.

Power delivery in accordance with the USB-PD specification(s) can beembodied in several different types of USB Type-C applications. Examplesof such types of Type-C applications include, but may not be limited to:a downstream facing port (DFP) application, in which an IC controllerwith a USB-PD subsystem is configured to provide a downstream-facing USBport (e.g., in a USB-enabled host device); an upstream facing port (UFP)application, in which an IC controller with a USB-PD subsystem isconfigured to provide an upstream-facing USB port (e.g., in aUSB-enabled peripheral device or adapter); a dual role port (DRP) USBapplication, in which an IC controller with a USB-PD subsystem isconfigured to support both DFP and UFP applications on the same USB port(e.g., a USB Type-C port that is configured to operate as either a powerprovider or a power consumer or can alternate between these two rolesdynamically by using USB-PD power role swap); and an active cableapplication, in which an IC controller with a USB-PD subsystem isdisposed into, and configured to operate, an electronically marked cableassembly (EMCA) Type-C cable.

The USB-PD specification defines, or otherwise allows, at least threedifferent voltage supplies that can be used by, or in, an IC controllerchip: VBUS (e.g., 3V-22.5V), VCONN (e.g., 3.0V-5.5V), and a localbattery supply (e.g., 2.0V-5.5V). The VBUS power supply draws power fromthe VBUS line of a USB-C connector and is typically used for poweringvarious USB functions. The VCONN power supply draws power from the VCONNline of the USB-C connector and is typically used for powering the USB-Cchip within a cable. The local battery supply draws power from a batteryand is typically used in DFP/UFP/DRP applications that can charge from aUSB port.

Since the VBUS, VCONN, and local battery supplies provide differentlevels of power for different purposes, electronic device manufacturersneed to use different types of IC controllers that are specificallydesigned to use a particular type of power supply depending on theparticular Type-C application. For example, some implementations ofUSB-enabled devices may use one type of a USB-C IC controller that ispowered from a local battery, while other implementations may use adifferent type of a USB-C IC controller that is powered from a VCONNsupply. Thus, electronic device manufactures lack design flexibility forsuch implementations since each design requires a specific type of USB-CIC controller chip. In addition, contemporary implementations of USB-CIC controllers are not able to power from VBUS supply without external,off-chip voltage regulators that reduce the VBUS supply voltage. Thus,such contemporary implementations also suffer from higherbill-of-materials (BOM) costs if the VBUS supply is to be used to powerthe IC controller chip. Further, according to the USB Type-Cspecification, the VBUS lines are disposed adjacent to respective VCONNlines within a USB-C connector (receptacle or plug). Due to this, aUSB-C IC controller is subject to short circuit risk between the VBUSand VCONN lines—e.g., because of misalignment between the cable plug andthe host receptacle as a result of bad manufacture, because of lowwiggle tolerance after the USB-C cable is plugged, etc. Thus, the VCONNpin of the IC controller needs to withstand a temporary short to theVBUS voltage, which can be more than 20V. However, contemporaryimplementations of USB-C IC controllers lack on-chip over-voltageprotection (OVP) on its VCONN pins, and typically use off-chip OVPcircuits which leads to increased BOM costs.

To address these and other disadvantages of contemporaneousimplementations, some embodiments of the power supply architecturedescribed herein provide for coupling a VCONN supply and a VBUS supplyof a USB-C IC controller to a common power rail that is coupled to aVDDD supply of the controller. As used herein, “power rail” refers toone or more conductive lines disposed on-chip that are configured toprovide power to internal circuits of an IC controller. In someembodiments, a power rail of an IC controller may be configured as apower bus that may include switches, regulators, pumps, logic, and othercircuits configured to selectively turn on/off power to internalcircuits and to convert standard voltages to other voltages asnecessary. “Logic” refers to a hardware block having one or morecircuits that include various electronic components configured toprocess analog and/or digital signals and to perform one or moreoperations in response to control signal(s). Examples of such electroniccomponents include, without limitation, transistors, diodes, resistors,capacitors, inductors, logic gates, and various circuits thereof.

According to the USB-C power supply architecture described herein, aVCONN switch with OVP circuit(s) is coupled between the common VDDDpower rail and a VCONN terminal (e.g., such as a VCONN pin) of a USB-CIC controller, and a VBUS regulator is coupled between the common VDDDpower rail and a VBUS terminal (e.g., such as a VBUS pin) of the ICcontroller. This architecture solution allows the same USB-C ICcontroller chip (e.g., a chip with the same or similar part number) tobe used in several different Type-C applications, thereby reducing BOMcost for electronic device manufacturers. For example, in an activecable application, the USB-C IC controller chip can be powered from theVCONN supply, and it can withstand and operate under voltages greaterthan 20V on both VBUS and VCONN pins of the controller (e.g., when theVCONN pin is temporarily shorted to the VBUS pin through the VBUS andVCONN lines the cable). In a DFP/UFP/DRP Type-C application, the same ICcontroller chip can be powered by either a VBUS supply applied to theVBUS pin of the chip or by a regulated power supply (e.g., a localbattery) applied to the VDDD pin of the controller chip, depending onwhichever is a more convenient design choice for the electronic devicemanufacturer.

In one embodiment of the USB-C power supply architecture describedherein, an IC controller disposed in a monolithic (e.g., single)semiconductor die is provided in a USB-enabled device. The IC controllercomprises a power rail, a VDDD terminal, a VCONN terminal, and a VBUSterminal. The VDDD terminal, the VCONN terminal, and the VBUS terminalare coupled to the power rail, where a VCONN switch is coupled betweenthe VCONN terminal and the power rail, and a VBUS regulator is coupledbetween the VBUS terminal and the power rail. The power rail is coupledto internal circuits of the IC controller and is configured to provideoperating power to the internal circuits from any one of the VCONNterminal and the VBUS terminal. In one example aspect of thisembodiment, the VCONN terminal of the IC controller is configured towithstand an input voltage of at least 20V. In another aspect, the VBUSterminal of the IC controller is configured for an input voltage between3.0V and 24.5V. In one aspect, the VCONN switch comprises adrain-extended n-type field effect transistor (DENFET) coupled betweenthe VCONN terminal and the power rail, and a pump switch coupled to agate of the DENFET. The VCONN switch may further comprise: a resistorcoupled between the VCONN terminal and the gate of the DENFET; a diodeclamp coupled between the gate of the DENFET and ground; and/or anelectro-static discharge (ESD) circuit coupled between the VCONNterminal and the gate of the DENFET. In one aspect the VBUS regulatorcomprises: one or more cascoded p-type field effect transistors (PFETs)coupled between the VBUS terminal and the power rail, wherein the one ormore cascoded PFETs are configured to reduce a voltage from the VBUSterminal to 5V or less; and one or more DENFETs coupled between the VBUSterminal and one or more low-voltage circuits of the VBUS regulator,wherein the one or more DENFETs are configured to provide high-voltageprotection to the low-voltage circuits. In this aspect, the one or morecascoded PFETs may be 5V transistors and the one or more DENFETs may be20V transistors.

In another embodiment, a USB-enabled device, apparatus, or systemcomprises an IC controller and a USB Type-C connector that includes aVBUS line and a VCONN line. The IC controller comprises a VDDD terminal,a VCONN terminal coupled to the VCONN line, a VBUS terminal coupled tothe VBUS line, and a power rail coupled to internal circuits of the ICcontroller. The VDDD terminal, the VCONN terminal, and the VBUS terminalare coupled to the power rail, where a VCONN switch is coupled betweenthe VCONN terminal and the power rail, and a VBUS regulator is coupledbetween the VBUS terminal and the power rail. The power rail isconfigured to provide operating power to the internal circuits of the ICcontroller from one of the VCONN terminal and the VBUS terminal. In oneaspect of this embodiment, the IC controller is configured to withstandan input voltage of at least 20V on the VCONN terminal. In anotheraspect, the IC controller is configured to receive an input voltagebetween 3.0V and 24.5V on the VBUS terminal. In various aspects, theUSB-enabled device may be a USB Type-C cable, a power adapter, or apower bank.

In another example embodiment, a method of operating an IC controller ina USB-enabled device comprises: receiving input voltage on one of aVCONN terminal and a VBUS terminal of the IC controller; and providing,via a power rail, operating power to internal circuits of the ICcontroller from the one of the VCONN terminal and the VBUS terminal. TheIC controller comprises the VCONN terminal, the VBUS terminal, the powerrail, and a VDDD terminal, where the VDDD terminal, the VCONN terminal,and the VBUS terminal are coupled to the power rail, and where a VCONNswitch is coupled between the VCONN terminal and the power rail, and aVBUS regulator is coupled between the VBUS terminal and the power rail.In an example aspect of this embodiment, receiving the input voltagecomprises receiving a voltage of at least 20V on the VCONN terminal as aresult of a short event between the VCONN terminal and the VBUSterminal. In this aspect, the method may further comprise limiting anoutput voltage from the VCONN switch to the power rail to no more than6V during the short event. In one aspect, receiving the input voltagecomprises receiving a voltage between 3.0V and 24.5V on the VBUSterminal. In an example aspect, receiving the input voltage comprisesreceiving a voltage of more than 5V on the VBUS terminal, and the methodfurther comprises the VBUS voltage regulator reducing the voltage on theVBUS terminal down to 5V or less on the power rail. In one aspect, themethod further comprises operating the VCONN switch and the VBUSregulator in a voltage range between 3.0V and 24.5V.

FIG. 1 illustrates an example semiconductor device that is configured inaccordance with the USB-C power supply architecture described herein. Inthe embodiment illustrated in FIG. 1, device 100 is a single-chip ICcontroller manufactured on a semiconductor die. For example, ICcontroller 100 may be a single-chip IC device from the family of CCGxxUSB controllers developed by Cypress Semiconductor Corporation, SanJose, Calif. In another example, IC controller 100 may be a single-chipIC that is manufactured as a System-on-Chip (SoC). In other embodiments,the IC controller 100 may be a multi-chip module encapsulated in asingle semiconductor package. Among other components, IC controller 100includes CPU subsystem 102, peripheral interconnect 114, systemresources 116, input/output (I/O) subsystem 118, USB-PD subsystem 120,and various terminals (e.g., pins) that are configured for receiving andsending signals.

CPU subsystem 102 includes one or more CPUs (central processing units)104, flash memory 106, SRAM (Static Random Access Memory) 108, and ROM(Read Only Memory) 110 that are coupled to system interconnect 112. CPU104 is a suitable processor that can operate in an IC or a SoC device.Flash memory 106 is non-volatile memory (e.g., NAND flash, NOR flash,etc.) that is configured for storing data, programs, and/or otherfirmware instructions. Flash memory 106 is tightly coupled within theCPU subsystem 102 for improved access times. SRAM 108 is volatile memorythat is configured for storing data and firmware instructions accessedby CPU 104. ROM 110 is read-only memory (or other suitable storagemedium) that is configured for storing boot-up routines, configurationparameters, and other firmware parameters and settings. Systeminterconnect 112 is a system bus (e.g., a single-level or multi-levelAdvanced High-Performance Bus, or AHB) that is configured as aninterface that couples the various components of CPU subsystem 102 toeach other, as well as a data and control interface between the variouscomponents of the CPU subsystem and peripheral interconnect 114.

Peripheral interconnect 114 is a peripheral bus (e.g., a single-level ormulti-level AHB) that provides the primary data and control interfacebetween CPU subsystem 102 and its peripherals and other resources, suchas system resources 116, I/O subsystem 118, and USB-PD subsystem 120.The peripheral interconnect 114 may include various controller circuits(e.g., direct memory access, or DMA controllers), which may beprogrammed to transfer data between peripheral blocks without burdeningthe CPU subsystem 102. In various embodiments, each of the components ofthe CPU subsystem and the peripheral interconnect may be different witheach choice or type of CPU, system bus, and/or peripheral bus.

System resources 116 include various electronic circuits that supportthe operation of IC controller 100 in its various states and modes. Forexample, system resources 116 may include a power subsystem havinganalog and/or digital circuits required for each controller state/modesuch as, for example, sleep control circuits, wake-up interruptcontroller (WIC), power-on-reset (POR), voltage and/or current reference(REF) circuits, etc. In some embodiments, the power subsystem may alsoinclude circuits that allow IC controller 100 to draw and/or providepower from/to external sources with several different voltage and/orcurrent levels and to support controller operation in several powerstates 117 (e.g., such as active state, sleep state, and a deep sleepstate with clocks turned off). Further, in some embodiments the CPUsubsystem 102 may be optimized for low-power operation with extensiveclock gating and may include various internal controller circuits thatallow the CPU to operate in the various power states 117. For example,the CPU may include a wake-up interrupt controller that is configured towake the CPU from a sleep state, thereby allowing power to be switchedoff when the IC chip is in the sleep state. System resources 116 mayalso include a clock subsystem having analog and/or digital circuits forclock generation and clock management such as, for example, clockcontrol circuits, watchdog timer (WDT) circuit(s), internal low-speedoscillator (ILO) circuit(s), and internal main oscillator (IMO)circuit(s), etc. System resources 116 may also include analog and/ordigital circuit blocks that provide reset control and support externalreset (XRES).

In various embodiments, I/O subsystem 118 may include various differenttypes of I/O blocks and subsystems. For example, in the embodimentillustrated in FIG. 1, I/O subsystem 118 includes GPIO (general purposeinput output) blocks 118 a, TCPWM (timer/counter/pulse-width-modulation)blocks 118 b, and SCBs (serial communication blocks) 118 c. GPIOs 118 ainclude analog and/or digital circuits configured to implement variousfunctions such as, for example, pull-ups, pull-downs, input thresholdselect, input and output buffer enabling/disabling, multiplex signalsconnected to various I/O pins, etc. TCPWMs 118 b include analog and/ordigital circuits configured to implement timers, counters, pulse-widthmodulators, decoders and various other analog/mixed signal elements thatare configured to operate on input/output signals. SCBs 118 c includeanalog and/or digital circuits configured to implement various serialcommunication interfaces such as, for example, I²C, SPI (serialperipheral interface), UART (universal asynchronousreceiver/transmitter), CAN (Controller Area Network) interface, CXPI(Clock eXtension Peripheral Interface), etc.

USB-PD subsystem 120 provides the interface to a USB Type-C port and isconfigured to support USB communications as well other USBfunctionality, such as power delivery and battery charging. USB-PDsubsystem 120 includes the electro-static discharge (ESD) protectioncircuits required on a Type-C port. USB-PD subsystem 120 also includes aType-C transceiver and physical layer logic (PHY), which are configuredas an integrated baseband PHY circuit to perform various digitalencoding/decoding functions (e.g., Biphase Mark Code-BMCencoding/decoding, cyclical redundancy checks-CRC, etc.) and analogsignal processing functions involved in physical layer transmissions.USB-PD subsystem 120 also provides the termination resistors (R_(P) andR_(D)) and their switches, as required by the USB-PD specification, toimplement connection detection, plug orientation detection, and powerdelivery roles over a Type-C cable. IC controller 100 (and/or the USB-PDsubsystem 120 thereof) may also be configured to respond tocommunications defined in a USB-PD Specification such as, for example,SOP (start-of-packet), SOP′, and SOP″ messaging.

Among other circuitry, USB-PD subsystem 120 may further include: one ormore analog-to-digital convertors (ADCs) for converting various analogsignals to digital signals; an error amplifier (ERROR AMP) forcontrolling the power source voltage applied to the VBUS line per a PDcontract; a high voltage regulator (HV REG) for converting the powersupply voltage to the precise voltage (e.g., 3-5V) needed to power ICcontroller 100; a current sense amplifier (CSA) and an over-voltageprotection (OVP) circuits for providing over-current and over-voltageprotection on the VBUS line with configurable thresholds and responsetimes; one or more gate drivers (GATE DRV) for controlling the powerswitches that turn on and off the provision of power over the VBUS line;a communication channel PHY (CC BB PHY) logic for supportingcommunications on a Type-C Communication Channel (CC) line; and at leasttwo on-die discharge (VBUS DISCH) circuits that can discharge a VBUSline voltage to any of range of programmable voltage levels.

In accordance with the USB-C power supply architecture described herein,USB-PD subsystem 120 includes a VCONN switch (VCONN SW) and a VBUSregulator (VBUS REG). The VCONN switch is coupled between a VCONN pin ofIC controller 100 and a common power rail. The VBUS regulator is coupledbetween a VBUS pin of IC controller 100 and the common power rail. Thecommon power rail is coupled to a VDDD pin of IC controller 100 and isconfigured to provide power to internal circuits of the controller. Forexample, the common (e.g., VDDD) power rail may be configured to providepower from any one of the VCONN, VBUS, or VDDD pins to some (or all) ofthe analog and/or digital circuits in system resources 116, I/Osubsystem 118, and USB-PD subsystem 120 that operate in the range of2.0V to 5.5V.

FIG. 2 illustrates a schematic diagram of an IC controller (e.g., suchas IC controller 100 in FIG. 1) in accordance with the USB-C powersupply architecture described herein. IC controller 100 includes VDDDpin 202, VCONN pin 204 and VBUS pin 206, which all are coupled (directlyor indirectly) to common power rail 210 and are configured to receiveinput voltage signals for powering the IC controller. In this manner, ICcontroller 100 can be powered from three separate possible powersupplies—VCONN, VBUS, or VDDD, depending on the design needs ofelectronic device manufacturers. The configuration of IC controller 100determines which one of the VCONN, VBUS, or VDDD supplies would powerthe chip—e.g., by means of a bit or bits in configuration firmware thatcontrols operation of the controller and its circuits. For example, insome USB-PD applications IC controller 100 can be powered from the VBUSor VCONN pin, with the VDDD pin left floating. In other USB-PDapplications, the IC controller 100 can be powered from the VDDD pin,with the VBUS and VCONN pins left floating or grounded.

VCONN switch 220 is coupled between VCONN pin 204 and the common powerrail 210, and is controlled by hardware digital blocks and logic. VCONNswitch 220 is configured to convert the input voltage (e.g., in therange 3.0V-5.5V) on VCONN pin 204 to a voltage within the VDDD voltagerange (e.g., 2.0V-5.5V) that is required on power rail 210. VCONN switch220 is also configured to provide OVP protection and InternationalElectrochemical Commission (IEC) ESD protection for any circuits thatare powered from power rail 210. The OVP and IEC-ESD circuits in VCONNswitch 220 limit the voltage that the output provides on power rail 210and protects against excessive voltage on the VCONN supply line due totransmission effects (e.g., such as ringing). In this manner, VCONN pin204 can withstand and operate at voltages above 20V, while also beingable to provide power to the internal circuits of IC controller 100.

VBUS regulator 230 is coupled between VBUS pin 206 and the common powerrail 210, and is controlled by hardware digital blocks and logic. VBUSregulator 230 is configured to convert the input voltage (e.g., in therange 3.0V-24.5V) on VBUS pin 206 to a voltage within the VDDD voltagerange (e.g., 2.0V-5.5V) that is required on power rail 210. VBUSregulator 230 is also configured to provide OVP protection for anycircuits that are powered from power rail 210. In this manner, ICcontroller 100 is configured to be powered from its VBUS pin 206 for allPD contracts allowable on a VBUS line, e.g., from 3V up to at least 20Vas specified in the USB-PD specification.

Common power rail 210 is coupled to provide power to VDDD core circuitry208. VDDD core circuitry 208 may include some (or all) internal circuitsof IC controller 100. For example, core circuitry 208 may includevarious low-voltage analog circuits that require input voltage in therange of 2.0V-5.5V. Core circuitry 208 may also include variouslow-voltage digital circuits that require input voltage of up to 1.8V.Such analog and/or digital circuits may be included in varioussubsystems of IC controller 100 (e.g., such as circuits in the power andclock subsystems in systems resources 116, circuits in I/O subsystem118, and circuits in USB-PD subsystem 120 that were described withrespect to FIG. 1 above), including any voltage regulators and othercircuits that operate to lower the voltage on power rail 210 to voltagethat is required to power digital logic of the controller.

The USB-C power supply architecture illustrated in FIG. 2 allows ICcontroller 100 to be powered from one of three power supplies related tothe USB-PD specification: VBUS, VCONN, or VDDD. The VBUS supply is themain power supply from a USB power provider and can range from 3V to24.5V in normal operation (and up to ˜30V for absolute max). It can beused in DFP/UFP/DRP Type-C applications to power the internal circuitsof the IC controller without the use of an external, off-chip voltageregulator. The VCONN supply is the voltage supply provided through theUSB-C connector of an EMCA cable/dongle, and can be used by thecable/dongle as the power source for the internal circuits of the ICcontroller. The voltage range of the VCONN supply is also from 3V to24.5V, because it can temporarily be shorted to the VBUS supply undercertain events. The VCONN supply also can be used in an EMCA cable topower the internal circuits of the IC controller without the use of anexternal, off-chip voltage regulator. The VDDD supply can be a powersupply derived from an electronic device's local battery. Its voltagerange is typically from 2.0V to 5.5V and can be used to power theinternal circuits of the IC controller in any Type-C applications with alocal battery per the design choices of the electronic devicemanufacturers.

FIG. 3 illustrates a schematic diagram of an example VCONN switch (e.g.,such as VCONN switch 220 in FIG. 2) in accordance with the USB-C powersupply architecture described herein. As illustrated in FIG. 3, VCONNswitch 220 is coupled between VCONN pin 204 and common power rail 210.Power rail 210 is coupled to provide power to the circuits in corecircuitry 208.

VCONN switch 220 includes DENFET 310, pump switch 320, pull-up resistor330, diode clamp 340, on-chip ESD circuit 350, and may also include acharge pump and control logic (not shown). DENFET 310 is a 20Vtransistor, which means that it can withstand a voltage of at least 20Vbetween its drain and its gate. Its extended drain is coupled to VCONNpin 204 and its source is coupled to power rail 210 (e.g., through asuitable resistor). The gate of DENFET 310 is coupled (through pull-upresistor 330) to VCONN pin 204, to the output of pump switch 320, and tothe input of diode clamp 340. Pump switch 320 is configured to receive avoltage signal (“vpump”) from a charge pump (not shown), and to applythe voltage signal to the gate of DENFET 310. The operation of pumpswitch 320 is controlled by two control signals (“sw_disable” and“sw_en_act”), which determine the three operational states of pumpswitch 320 (power-up, active and disabled). Pull-up resistor 330 iscoupled between VCONN pin 204 and the gate of DENFET 310, and has aresistance (e.g., 1 MΩ) that is suitable to pull-up the DENFET gate whenvoltage is applied on VCONN pin 204. Diode clamp 340 is coupled betweenthe gate of DENFET 310 and ground, and is configured to clamp thevoltage applied on the DENFET gate, in the event where VCONN shorts toVBUS. ESD circuit 350 is coupled to VCONN pin 204 and uses a GateInduced Drain Leakage (GIDL)-based architecture to implement ESDprotection to prevent an over-current surge on the VCONN pin 204.

In operation, DENFET 310 acts as a power switch between VCONN pin 204and common power rail 210. During normal operation, the gate of DENFET310 is either weakly pulled up to the voltage on VCONN pin 204 throughthe resistor 330, or it is pulled up to a ˜5V pump voltage signal(“vpump”) that is applied to the DENFET gate through pump switch 320.The pump voltage is such that it can fully turn on DENFET 310, which hasat least two benefits. First, the “on” resistance of DENFET 310 isminimized when current is supplied from VCONN pin 204 to power rail 210.Second, the pump voltage limits the voltage provided to power rail 210when the VCONN input is shorted to the VBUS voltage (e.g., 20V). SinceDENFET 310 cannot pass through a voltage higher than Vgs=Vg−Vt (where Vgis the DENFET gate voltage, Vgs is the gate to source voltagedifference, and Vt is the DENFET threshold voltage), applying the pumpvoltage to the gate of the DENFET effectively limits the voltageprovided to power rail 210 to less than 5V.

In addition, during a short event between the input voltage on VCONN pin204 and the VBUS voltage (e.g., up to 24.5V, or even ˜30V max), diodeclamp 340 limits the voltage on the gate of DENFET 310 to no more than6V. This protects the DENFET gate and limits the output voltage providedon power rail 210 to less than 6V. There is no voltage detectioncircuitry necessary, and these circuits of VCONN switch 220 can operateindefinitely in the 3.0V to 24.5V range. Further, during a VBUS shortevent, ESD circuit 350 acts as another clamp on VCONN pin 204 and thusany ringing on the VCONN pin is limited to no more than ˜30V since thecircuit starts clamping around that voltage. (“Ringing” here refers tothe oscillation of the VCONN input signal in the response to a suddenchange in input, e.g., the short event.) If no ESD protection isprovided for VCONN switch 220, such ringing can cause a voltage increaseof up to 2× (e.g., up to ˜40V if a PD contract requires VBUS to providethe maximum 20V specified in the USB-PD specification).

FIG. 4 illustrates a schematic diagram of an example VBUS regulator(e.g., such as VBUS regulator 230 in FIG. 2) in accordance with theUSB-C power supply architecture described herein. As illustrated in FIG.4, VBUS regulator 230 is coupled between VBUS pin 206 and common powerrail 210. Power rail 210 is coupled to VDDD pin 202, and also to thecircuits in core circuitry 208 to provide power thereto. When ICcontroller 100 is configured to be powered from VBUS pin 206, VDDD pin202 should be left floating and may be coupled through an off-chipcapacitor 203 to ground. Off-chip capacitor 203 should have a suitablecapacitance (e.g., 1 μF) to provide stability and to improve thetransient response on VDDD pin 202. VBUS regulator 230 includes adifferential error amplifier, a voltage buffer, and an output block thatare coupled in a feedback loop and are configured to provide a fixedvoltage to power rail 210.

Diode-connected transistors 412, PFET 414, protection DENFETs 416,amplifier 418, and current source 420 are configured to operate as thedifferential error amplifier of VBUS regulator 230. Diode-connectedtransistors 412 are PFETs coupled to VBUS pin 206 and are configured tomirror the VBUS voltage on both sides of the differential erroramplifier. PFET 414 is coupled between the output of one of transistors412 and protection DENFETs 416, and its gate is coupled to receive abias voltage control signal (“biasp1”). The output of PFET 414 iscoupled as an input signal to the gate of source follower 424.Protection DENFETs 416 are configured to provide high-voltage protectionto the low-voltage circuits in amplifier 418 and current source 420. Thegates of DENFETs 416 are coupled to receive a bias voltage controlsignal (“biasn1”). The input (left) side of amplifier 418 is coupled toreceive a feedback voltage (“Vfb”) signal from resistor divider 438. Thereference (right) side of amplifier 418 is coupled to receive areference voltage (“vref”), which is compared to the feedback voltage(“Vfb”) received from resistor divider 438. The output of amplifier 418is coupled to current source 420. Current source 420 is a constantcurrent source and is coupled to provide constant current through thedifferential error amplifier.

Cascoded transistors 422, source follower 424, DENFET 426, and currentsource 428 are configured to operate as a voltage buffer to transfer theoutput signal from the differential error amplifier to the output blockof VBUS regulator 230. Cascoded transistors 422 are PFETs coupled inseries between VBUS pin 206 and the gate of source follower 424, and areconfigured to provide protection against transient voltage fluctuationsof the VBUS voltage. Source follower 424 is a N-Type Field EffectTransistor (NFET), and its gate is coupled to receive input voltage fromPFET 414. The output of source follower 424 is coupled to DENFET 426 andto the gate of pass transistor 434. The gate of DENFET 426 is coupled toreceive a bias voltage control signal (“biasn1”). DENFET 426 isconfigured to provide high-voltage protection to the low-voltagecircuits in current source 428. Current source 428 is a constant currentsource, which is coupled to the source of DENFET 426 and is configuredto provide constant current through the voltage buffer of VBUS regulator230.

Cascoded transistors 432, pass transistor 434, PFETs 436, and resistordivider 438 are configured to operate as the output block of VBUSregulator 230. Cascoded transistors 432 are PFETs coupled in seriesbetween VBUS pin 206 and the gate of pass transistor 434, and areconfigured to provide protection against transient voltage fluctuationsof the VBUS voltage. Pass transistor 434 is a PFET, and its gate iscoupled to the output of source follower 424. The source of passtransistor 434 is coupled to VBUS pin 206, and the drain of the passtransistor is coupled as input to PFETs 436. PFETs 436 are cascoded PMOSdevices coupled in series. PFETs 436 are configured to reduce thevoltage received from VBUS pin 206 to the lower, fixed voltage that isrequired by power rail 210 (e.g., down to less than 5V), thereby alsoproviding high-voltage protection to the output block of VBUS regulator230. Each of the gates of PFETs 436 is coupled to receive a respectivebias voltage control signal (“biasp1”, “biasp2”, “biasp3”, “biasp4”,etc.). The output of PFETs 436 is coupled to power rail 210 and toresistor divider 438. The resistors in resistor divider 438 are selectedto provide a fixed-ratio offset from the voltage on power rail 210.

In the embodiment illustrated in FIG. 4, the bias voltage controlsignals (e.g., (“biasp1”, “biasp2”, “biasp3”, “biasp4”) provided to thePFET transistors (e.g., PFET 414 and PFETs 436) are generated from 20Vbias generation circuits (not shown) that are powered by the VBUSvoltage. The voltage of each bias voltage control signal is generatedbased on the VBUS voltage, so these bias voltages dynamically change asthe VBUS voltage changes (e.g., in response to a re-negotiated PDcontract). VBUS regulator 230 also includes a crude voltage regulatorblock (not shown in FIG. 4) that is configured to generate various biasvoltages in the range of 2.0V-5.5V from the VBUS voltage on VBUS pin206. The output from the crude voltage regulator block is used as thesupply for various logic blocks and to generate the bias voltage controlsignals (e.g., such as “biasn1”) that are provided to the protectionDENFETs 416 and 426. The transistors in protection DENFETs 416 and 426are 20V drain extended NMOS devices, and the majority of the othertransistor devices in VBUS regulator 230 (e.g., transistors 412, 418,422, 424, 432, 434, and 436) are 5V-compatible, which means that theycan tolerate approximately 5V across any of its terminals.

The voltage required on power rail 210 is fixed by the design of the ICcontroller. The resistors in resistor divider 438 are selected toprovide a fixed-ratio offset from the voltage on power rail 210. Thisfixed-ratio voltage across resistor divider 438 is the feedback voltage(“Vfb”) that is input to amplifier 418 and is compared to the referencevoltage (“vref”) of the amplifier. In the steady operational state ofVBUS regulator 230, the reference voltage (“vref”) and the feedbackvoltage (“Vfb”) across resistor divider 438 are equal, so amplifier 418is balanced and the currents flowing through its input (left) andreference (right) sides are also equal. In an example embodiment, thedesign-fixed voltage on power rail 210 is set at 3.3V, and in the steadyoperational state the feedback voltage (“Vfb”) and the reference voltage(“vref”) are both equal to 0.74V.

When the voltage on power rail 210 is momentary pulled down (e.g., whenan internal circuit in core circuitry 208 is turned on), the feedbackvoltage (“Vfb”) across resistor divider 438 goes lower than thesteady-state reference voltage (“vref”). As a result, the voltage on thegate of the input (left) side of amplifier 418 goes lower and itconducts less current than in the steady-state. To compensate, currentsource 420 pulls more current through the reference (right) side ofamplifier 418. This causes more current to be pulled from the gate ofsource follower 424 (since, under the control of its bias control signal“biasp1”, PFET 414 always conducts a fixed amount of current). Drawingmore current from the gate of source follower 424 causes its gatevoltage to go lower than in the steady-state, which in turn causessource follower 424 to conduct less current. To compensate, currentsource 428 draws more current from the gate of pass transistor 434 thanin the steady-state. Drawing more current from the gate of passtransistor 434 causes its gate voltage to go lower than in thesteady-state, which in turn causes the pass transistor to conduct morecurrent than in the steady-state (since pass transistor 434 is a PFET).Thus, more current is provided to the input of PFETs 436, and as aresult the voltage output by PFETs 436 to power rail 210 is pulled up.The VBUS regulator 230 operates like this for a short time until thevoltage on power rail 210 is pulled up to its required voltage. In thismanner, VBUS regulator 230 pulls up the voltage level on power rail 210after it has momentarily gone down.

When the voltage on power rail 210 is momentary pulled up (e.g., when aninternal circuit in core circuitry 208 is turned off), the feedbackvoltage (“Vfb”) across resistor divider 438 goes higher than thesteady-state reference voltage (“vref”). As a result, the voltage on thegate of the input (left) side of amplifier 418 goes higher and itconducts more current than in the steady-state. To compensate, currentsource 420 pulls less current through the reference (right) side ofamplifier 418. This causes less current to be pulled from the gate ofsource follower 424 (since, under the control of its bias control signal“biasp1”, PFET 414 always conducts a fixed amount of current). Drawingless current from the gate of source follower 424 causes its gatevoltage to go higher than in the steady-state, which in turn causessource follower 424 to conduct more current. To compensate, currentsource 428 draws less current from the gate of pass transistor 434 thanin the steady-state. Drawing less current from the gate of passtransistor 434 causes its gate voltage to go higher than in thesteady-state, which in turn causes the pass transistor to conduct lesscurrent than in the steady-state (since pass transistor 434 is a PFET).Thus, less current is provided to the input of PFETs 436, and as aresult the voltage output by PFETs 436 to power rail 210 is pulled down.The VBUS regulator 230 operates like this for a short time until thevoltage on power rail 210 is pulled down to its required voltage. Inthis manner, VBUS regulator 230 pulls down the voltage level on powerrail 210 after it has momentarily gone up.

According to the USB-C power supply architecture described herein, thesame IC chip product may be disposed in an active Type-C cableapplication as a cable controller powered from its VCONN pin (e.g., asillustrated in FIGS. 5A and 5B) and in a DFP/UFP/DRP application as aUSB-C controller powered from its VBUS pin (e.g., as illustrated in FIG.6) or from a regulated local power supply (e.g., such as battery). Thisallows the same IC chip product to be used for multiple USB Type-C andUSB-PD applications such as active cables, power adapters, power banks,etc., thereby reducing the BOM costs and providing more designflexibilities to electronic device manufacturers.

FIGS. 5A and 5B collectively illustrate a schematic diagram of an EMCAcable assembly that embodies the USB-C power supply architecturedescribed herein. Specifically, FIG. 5A illustrates one end of a USBType-C cable 500 and FIG. 5B illustrates the other end of the samecable. Two IC controllers 100A and 100B, both powered from the VCONNline of cable 500, are disposed as cable controllers at the respectiveends of the cable. In the embodiment of FIGS. 5A and 5B, cable 500 isconfigured to transfer multiple different types of communications overits lines. For example, cable 500 supports a tunneling protocol thatprovides multiple types of communications—e.g., PCI-Express (PCI-E),Display Port (DP), and USB 3.0+ (e.g., 10 GB+)—over its SSTX and SSRXlines. In use, one end of cable 500 may be plugged into a host device(e.g., a laptop, a notebook, a desktop computer, etc.), and the otherend may be plugged into a peripheral device (e.g., a docking station, amonitor, etc.) The host device bundles the different types ofcommunications and tunnels them over the lines of cable 500 to theperipheral device, and the peripheral device un-bundles them back uponreceipt at the other end.

As illustrated in FIG. 5A, USB-C plug 540A, IC controller 100A, andclock and data recovery (CDR) chip 535A are disposed within one end ofUSB-C cable 500. As illustrated in FIG. 5B, USB-C plug 540B, ICcontroller 100B, and CDR chip 535B are disposed within the other end ofcable 500. Cable 500 includes SSTX lines, SSRX lines, SBU1 and SBU2lines, and a ground GND line (among others) that are routed from plug540A at one end of the cable to plug 540B at the other end of the cable.The ground GND line runs across from plug 540A to plug 540B. The SSTXlines, the SSRX lines, and the SBU1 and SBU2 lines are routed from plug540A to plug 540B via CDR chips 535A and 535B. Each of CDR chips 535Aand 535B includes various components (e.g., such as repeaters, bridges,etc.) that are configured to re-time and re-condition the signals on theSSTX, SSRX, and SBU lines.

Referring to FIG. 5A, the VDDD pin 202A of IC controller 100A is coupledto ground through a suitable capacitor (e.g., 1 μF), which providesstability and improves the transient response on the VDDD pin. TheVBUS_IN pin 206A is left floating. Four input/output pins of ICcontroller 100A (“GDR_GPIO1”, “GDR_GPIO2”, “GDR_GPIO3”, “GDR_GPIO4”) arecoupled to respective pins of CDR chip 535A for data, control, and powerthereto. The VCONN line of plug 540A is connected to VCONN pin 204A ofIC controller 100A. In accordance with the USB-C power supplyarchitecture described herein, VCONN pin 204A is coupled through a VCONNswitch to the VDDD power rail of IC controller 100A. In operation, ICcontroller 100A is configured to receive input voltage on VCONN pin 204Aand to provide operating power, via the VDDD power rail, to the internalcircuits of the IC controller.

Referring to FIG. 5B, the VDDD pin 202B of IC controller 100B is coupledto ground through a suitable capacitor (e.g., 1 μF), which providesstability and improves the transient response on the VDDD pin. TheVBUS_IN pin 206B is left floating. Four input/output pins of ICcontroller 100B (“GDR_GPIO1”, “GDR_GPIO2”, “GDR_GPIO3”, “GDR_GPIO4”) arecoupled to respective pins of CDR chip 535B for data, control, and powerthereto. The VCONN line of plug 540B is connected to VCONN pin 204B ofIC controller 100B. In accordance with the USB-C power supplyarchitecture described herein, VCONN pin 204B is coupled through a VCONNswitch to the VDDD power rail of IC controller 100B. In operation, ICcontroller 100B is configured to receive input voltage on VCONN pin 204Band to provide operating power, via the VDDD power rail, to the internalcircuits of the IC controller.

FIG. 6 illustrates a schematic diagram of a USB-PD power adapter 600 asa DFP/UFP/DRP Type-C application that embodies the USB-C power supplyarchitecture described herein. According to the USB-PD specification, apower adapter can be configured to deliver power (e.g., up to 5 A ofcurrent at up to 20V, for a total of up to 100 W) to another devicethrough a power path configured on a USB-C VBUS line. The device thatprovides power over a USB-C VBUS line is typically referred to as (orincludes) a “power provider”, and the device that consumes the providedpower is typically referred to as (or includes) a “power consumer”.

In FIG. 6, USB-PD power adapter 600 includes IC controller 100, USBType-C connector 640, power converter 650, and secondary controller 660.IC controller 100 includes a USB-PD subsystem as described heretoforeand is configured to negotiate a PD contract with a power consumer (notshown) attached to USB Type-C connector 640. In various embodiments, USBType-C connector 640 may be a Type-C plug or a Type-C receptacle. Powerconverter 650 is an AC power source and includes a large bulk capacitorconfigured to remove the AC component of the power signal provided ontoVBUS line 601. Power converter 650 is coupled to secondary controller660, which is configured to control the voltage provided by the powerconverter based on a feedback signal from an output pin (“FB”) of ICcontroller 100. IC controller 100 supports two modes of operation,constant voltage mode and constant current mode (also referred to asdirect charging mode). Upon appropriate negotiation with a powerconsumer device through the CC1 line of USB Type-C connector 640, ICcontroller 100 switches between its two modes of operation and providesthe appropriate feedback signal on its output pin “FB” to control theoperation of secondary controller 660.

Power adapter 600 includes a power switch 603 on its VBUS line 601.Power switch 603 is configured as an on/off switch device controlled bysignals from an output pin (“VBUS_P_CTRL”) of a gate driver in ICcontroller 100. In operation, the direction of power flow on VBUS line601 is from power converter 650 to a power consumer (e.g., such as amobile phone, not shown) that is attached to USB Type-C connector 640.When a PD contract with the power consumer is negotiated, IC controller100 turns on power switch 603 to provide power to the consumer device atthe negotiated voltage and/or current level(s).

In accordance with the USB-C power supply architecture described herein,IC controller 100 is powered from the VBUS line 601 of power adapter600. VDDD pin 202 of IC controller 100 is coupled to ground through asuitable capacitor (e.g., 1 μF), which provides stability and improvesthe transient response on the VDDD pin. The VCONN pin 204 is connectedto a corresponding pin in USB Type-C connector 640. The VBUS line 601 ofpower adapter 600 is connected to VBUS_IN pin 206 of IC controller 100.In accordance with the USB-C power supply architecture described herein,VBUS_IN pin 206 is coupled through a VBUS regulator to the VDDD powerrail of IC controller 100. In operation, IC controller 100 is configuredto receive input voltage on VBUS_IN pin 206 and to provide operatingpower, via the VDDD power rail, to the internal circuits of the ICcontroller.

The USB-C power supply architecture described herein allows one IC chipproduct to be embodied in multiple different USB Type-C and USB-PDapplications (e.g., such as EMCA cables, power adaptors, power banks,etc.) that have different power supply requirements. The IC chip productcan be powered from three possible power supplies: VBUS, VCONN, andVDDD. The VCONN pin of the chip can operate at voltages above 20V andhas IEC ESD protection that limits the voltage on the VCONN supply linedue to transmission line effects (e.g., such as ringing). The chip alsosupports powering of its internal circuits from its VBUS pin for all PDcontracts allowed under the USB-PD specification, e.g., from 3V up to20V. Such power supply architecture also provides BOM cost reductionsince all of the features can be integrated into a single IC controllerto support all of the three power supplies.

FIG. 7 illustrates a schematic diagram of a VCONN switch according to analternative embodiment of the USB-C power supply architecture describedherein. VCONN switch 720 is coupled between VCONN pin 204 and commonpower rail 210. Power rail 210 is coupled to provide power to thecircuits in core circuitry 208.

VCONN switch 720 includes NFET 722, Zener diode 724, and pull-upresistor 726. The drain of NFET 722 is coupled to VCONN pin 204 and itssource is coupled to power rail 210. The gate of NFET 722 is coupledthrough pull-up resistor 726 to VCONN pin 204 and to the output of Zenerdiode 724. Pull-up resistor 726 has a resistance that is suitable forweak pull-up of the NFET gate when voltage is applied on VCONN pin 204.Zener diode 724 is coupled between the gate of NFET 722 and ground.Unlike a normal diode, Zener diode 724 has a highly doped p-n junctionthat allows current to flow not only from its anode to its cathode, butalso in the reverse direction (e.g., when its Zener voltage is reached).In operation, the gate of NFET 722 is controlled by the weak pull-upresistor 726 to the supply voltage provided on VCONN pin 204, and Zenerdiode 724 prevents the gate voltage from going too high. This allows theinput voltage on VCONN pin 204 to be applied to power rail 210 in orderto power the internal circuits of core circuitry 208.

In the embodiment of FIG. 7 and/or in other alternative embodiments, anexternal off-chip OVP circuit may be used to protect the VCONN pin fromVBUS short events. FIG. 8 illustrates a schematic diagram of suchalternative embodiments, which may be useful for semiconductormanufacturers that have only 5V transistor circuits at their disposal.

In FIG. 8, IC controller 800 includes VDDD pin 802, VCONN pin 804 andVBUS pin 806, which all are coupled (directly or indirectly) to commonpower rail 810 and are configured to receive input voltage signals forpowering core circuitry 808. VCONN switch 820 is coupled between VCONNpin 804 and the common power rail 810. VCONN switch 820 is configured toprovide a stable voltage within the VDDD voltage range (e.g., 2.0V-5.5V)to power rail 810. VBUS regulator 830 is coupled between VBUS pin 806and the common power rail 810. VBUS regulator 830 is configured toconvert the input voltage (e.g., in the range 3.0V-24.5V) on VBUS pin806 to a voltage within the VDDD voltage range (e.g., 2.0V-5.5V) that isrequired on power rail 810.

An external off-chip OVP circuit 805 is provided to connect VCONN pin804 to the VCONN power supply (not shown). OVP circuit 805 includes alow-resistance switch that prevents a high voltage IR drop, which allowsVCONN switch 820 to operate normally in the 5V range. When a VBUS shortevent occurs in operation, the VCONN supply path is shut off by OVPcircuit 805, thereby providing high-voltage protection to VCONN switch820 and the internal circuits of core circuitry 808.

Various embodiments of the USB-C power supply architecture describedherein may include various operations. These operations may be performedand/or controlled by hardware components, digital hardware and/orfirmware, and/or combinations thereof. As used herein, the term “coupledto” may mean connected directly or connected indirectly through one ormore intervening components. Any of the signals provided over variouson-die buses may be time multiplexed with other signals and providedover one or more common on-die buses. Additionally, the interconnectionbetween circuit components or blocks may be shown as buses or as singlesignal lines. Each of the buses may alternatively be one or more singlesignal lines and each of the single signal lines may alternatively bebuses.

Certain embodiments may be implemented as a computer program productthat may include instructions stored on a non-transitorycomputer-readable medium, e.g., such as volatile memory and/ornon-volatile memory. These instructions may be used to program and/orconfigure one or more devices that include processors (e.g., CPUs) orequivalents thereof (e.g., such as processing cores, processing engines,microcontrollers, and the like), so that when executed by theprocessor(s) or the equivalents thereof, the instructions cause thedevice(s) to perform the described operations for USB-C power supplyarchitecture described herein. A computer-readable medium may alsoinclude one or more mechanisms for storing or transmitting informationin a form (e.g., software, processing application, etc.) that isreadable by a machine (e.g., such as a device or a computer). Thenon-transitory computer-readable storage medium may include, but is notlimited to, electromagnetic storage medium (e.g., floppy disks, harddisks, and the like), optical storage medium (e.g., CD-ROM),magneto-optical storage medium, read-only memory (ROM), random-accessmemory (RAM), erasable programmable memory (e.g., EPROM and EEPROM),flash memory, or another now-known or later-developed non-transitorytype of medium that is suitable for storing information.

Although the operations of the circuit(s) and block(s) herein are shownand described in a particular order, in some embodiments the order ofthe operations of each circuit/block may be altered so that certainoperations may be performed in an inverse order or so that certainoperation may be performed, at least in part, concurrently and/or inparallel with other operations. In other embodiments, instructions orsub-operations of distinct operations may be performed in anintermittent and/or alternating manner.

In the foregoing specification, the invention has been described withreference to specific exemplary embodiments thereof. It will, however,be evident that various modifications and changes may be made theretowithout departing from the broader spirit and scope of the invention asset forth in the appended claims. The specification and drawings are,accordingly, to be regarded in an illustrative sense rather than arestrictive sense.

What is claimed is:
 1. An integrated circuit (IC) controller for aUniversal Serial Bus (USB) Type-C device, the IC controller comprising:a power rail coupled to internal circuits of the IC controller; and aVDDD terminal, a VCONN terminal, and a VBUS terminal that are coupled tothe power rail, wherein: a VCONN switch is coupled between the VCONNterminal and the power rail; and a VBUS regulator is coupled between theVBUS terminal and the power rail; wherein the power rail is configuredto provide operating power to the internal circuits of the IC controllerfrom any one of the VCONN terminal and the VBUS terminal.
 2. The ICcontroller of claim 1, wherein the VCONN terminal is operable towithstand an input voltage of at least 20V.
 3. The IC controller ofclaim 1, wherein the VBUS regulator comprises: one or more cascodedp-type field effect transistors (PFETs) coupled between the VBUSterminal and the power rail, wherein the one or more cascoded PFETs areconfigured to reduce a voltage from the VBUS terminal to less than 5V;and one or more drain-extended n-type field effect transistor (DENFETs)coupled between the VBUS terminal and one or more low-voltage circuitsof the VBUS regulator, wherein the one or more DENFETs are configured toprovide high-voltage protection to the low-voltage circuits.
 4. The ICcontroller of claim 1, wherein the VBUS terminal is configured for aninput voltage between 3.0V and 24.5V.
 5. The IC controller of claim 1,wherein the VCONN switch comprises: a drain-extended n-type field effecttransistor (DENFET) coupled between the VCONN terminal and the powerrail; and a pump switch coupled to a gate of the DENFET.
 6. The ICcontroller of claim 5, the VCONN switch further comprises: a resistorcoupled between the VCONN terminal and the gate of the DENFET; and adiode clamp coupled between the gate of the DENFET and ground.
 7. The ICcontroller of claim 5, further comprising an ESD circuit coupled betweenthe VCONN terminal and the gate of the DENFET.
 8. The IC controller ofclaim 3, wherein the one or more PFETs are 5V transistors and the one ormore DENFETs are 20V transistors.
 9. A Universal Serial Bus (USB) devicecomprising: a USB Type-C connector comprising a VBUS line and a VCONNline; and an integrated circuit (IC) controller comprising: a VDDDterminal; a VCONN terminal coupled to the VCONN line of the USB Type-Cconnector; a VBUS terminal coupled to the VBUS line of the USB Type-Cconnector; and a power rail coupled to internal circuits of the ICcontroller; wherein the VDDD terminal, the VCONN terminal, and the VBUSterminal are coupled to the power rail, and wherein: a VCONN switch iscoupled between the VCONN terminal and the power rail; and a VBUSregulator is coupled between the VBUS terminal and the power rail;wherein the power rail is configured to provide operating power to theinternal circuits of the IC controller from one of the VCONN terminaland the VBUS terminal.
 10. The USB device of claim 9, wherein the ICcontroller is operable to withstand an input voltage of at least 20V onthe VCONN terminal.
 11. The USB device of claim 9, wherein the ICcontroller is configured to receive an input voltage between 3.0V and24.5V on the VBUS terminal.
 12. The USB device of claim 9, wherein theUSB device is a USB Type-C cable.
 13. The USB device of claim 9, whereinthe USB device comprises a power adapter.
 14. The USB device of claim 9,wherein the USB device comprises a power bank.
 15. A method of operatingan integrated circuit (IC) controller in a Universal Serial Bus (USB)Type-C device, the method comprising: receiving input voltage on one ofa VCONN terminal and a VBUS terminal of the IC controller; wherein theIC controller comprises the VCONN terminal, the VBUS terminal, a VDDDterminal, and a power rail coupled to internal circuits of the ICcontroller, wherein the VDDD terminal, the VCONN terminal, and the VBUSterminal are coupled to the power rail, and wherein: a VCONN switch iscoupled between the VCONN terminal and the power rail; and a VBUSregulator is coupled between the VBUS terminal and the power rail; andproviding, via the power rail, operating power to the internal circuitsof the IC controller from the one of the VCONN terminal and the VBUSterminal.
 16. The method of claim 15, wherein receiving the inputvoltage comprises receiving a voltage of at least 20V on the VCONNterminal as a result of a short event between the VCONN terminal and theVBUS terminal.
 17. The method of claim 15, wherein receiving the inputvoltage comprises receiving a voltage between 3.0V and 24.5V on the VBUSterminal.
 18. The method of claim 15, wherein receiving the inputvoltage comprises receiving a voltage of more than 5V on the VBUSterminal, and the method further comprises the VBUS voltage regulatorreducing the voltage on the VBUS terminal down to less than 5V on thepower rail.
 19. The method of claim 15, further comprising operating theVCONN switch and the VBUS regulator in a voltage range between 3.0V and24.5V.
 20. The method of claim 16, further comprising limiting an outputvoltage from the VCONN switch to the power rail to no more than 6Vduring the short event.